Autumn Leaves - Myth and Reality

perennial beds, under trees or into a compost heap. Annual flower or vegetable gardens should be cleared of frost-killed vegetation (compost it), sown to a cover crop like annual rye or hairy vetch and left to grow all winter. The cover crop should be dug or tilled in the spring, and two weeks later seeds may be sown.

By the time long-season crops like corn or tomatoes are about 10 inches tall, the rough compost from the previous November's leaves may be spread 4 inches thick between the rows. It will pack down to about 2 inches thick, and can be dug or tilled in during the fall, before the new cover crop is sown, or in the spring. Freeze/thaw cycles, earthworms and other soil decomposers will help break down the leaves even further. Garden soil will turn black and rich in organic matter and fertility.

Leaves kept in bags until spring can be spread and tilled in then, just before seed is sown.

False. Seedlings won't grow well if the dirt is overloaded with unrotted leaves. Empty the bags, let leaves rot for 9 months. Weed seeds will be denied the light they need to sprout if you hoe or cultivate first, then mulch row middles with rotted leaves after plants are growing well.

Maple leaves rot faster than oak leaves.

True. Thin green nitrogen-rich maple leaves, which fall to the ground in early autumn, will rot quickly. Thicker oak leaves fall later and rot more slowly.

Scientists have found that fallen maple and oak leaves release natural phenols during the first 6 to 8 months of the rotting period. These phenols inhibit growth of seedling roots, but rot and disappear from soil and mulch within 9 months of weathering. Better to keep dead leaves and leaf compost out of an area where seeds will be sprouting until after plants are up and growing well.

Pine needles are a good, long lasting mulch for acid loving shrubs like azaleas and rhododendrons.

True. A resinous covering on the needles slows rotting. Pine needles can also be sprinkled in a thin layer over oak or other leaves to keep leaf mulches from blowing. Pine needles are best left under pine trees, where they protect roots from drying. Another way to keep a leaf mulch from blowing is to sprinkle it with water right after the mulch is laid down.

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